Posted for "Bob Jude" <bobjude@charter.net>:

 The most confusing part of this discussion is that no one is saying where the
pressure gage is connected.  Is it high side? Low side? Relative to ambient or
differential, high side to low side?  It seems to me that the only pressure
that really matters is the differential pressure (High side to low side coming
up and Low side to high side going down) because that is the pressure that
moves the cylinders.  If I had a pressure gage in my bird, it would definitely
be a differential gage.  I don't see any way that opening the dump valve would
not return the differential pressure to zero.  Now I'm just as confused as you
are.
 Bob Jude